<template>
  <view class="cate-view">
    <!-- 使用自定义的搜索组件 -->
    <my-search @click="gotoSearch"></my-search>
    <view class="scroll-view-container">
      <!-- 左侧的滑动区域 -->
      <scroll-view class="left-scroll-view" scroll-y="true" :style="{height: wh + 'px'}">
        <block v-for="(item,i) in cateList" :key="i">
          <view :class="['left-scroll-view-item', i === active ? 'active' : '']" 
          @click="activeChanged(i)">{{item.cat_name}}</view>
        </block>
      </scroll-view>
     <!-- 右侧的滑动区域 --> 
     <scroll-view class="right-scroll-view" scroll-y="true" :style="{height: wh + 'px'}" :scroll-top="scrollTop">
       <view class="cate-lv2" v-for="(item2,i2) in cateLevel2" :key="i2">
         <!-- 二级分类的标题 -->
         <view class="cate-lv2-title">/ {{item2.cat_name}} /</view>
         <!-- 当前二级分类下的三级分类列表 -->
         <view class="cate-lv3-list">
           <!-- 三级分类的Item项 -->
           <view class="cate-lv3-item" v-for="(item3,i3) in item2.children" :key="i3" @click="gotoGoodsList(item3)">
             <!-- 三级分类的图片 -->
             <image :src="item3.cat_icon"></image>
             <!-- 三级分类的文本 -->
             <text>{{item3.cat_name}}</text>
           </view>
         </view>
       </view>
     </scroll-view>
    </view>
  </view>
</template>

<script>
  import badgeMix from '@/mixins/tabbar-badge.js'
  
  export default {
    mixins:[badgeMix],
    data() {
      return {
        //当前设备可用的高度
        wh:0,
        cateList:[],
        active:0,
         // 二级分类列表
        cateLevel2: [],
        // 滚动条距离顶部的距离
        scrollTop: 0
      };
    },
    onLoad() {
      const sysInfo = uni.getSystemInfoSync()
      this.wh = sysInfo.windowHeight - 50
      
      this.getCateList()
    },
    methods:{
      //获取分类列表的数据
      async getCateList(){
        const {data:res} = await uni.$http.get('/api/public/v1/categories')
        if(res.meta.status !== 200) return uni.$showMsg()
        this.cateList = res.message
        
        //为二级分类赋值
        this.cateLevel2 = res.message[0].children
      },
      activeChanged(i){
        this.active = i
        
        //重新为二级分类赋值
        this.cateLevel2 = this.cateList[i].children
        
        this.scrollTop = this.scrollTop ? 0 : 1
      },
      //跳转到商品列表页面
      gotoGoodsList(item){
        uni.navigateTo({
          url:'/subpkg/goods_list/goods_list?cid=' + item.cat_id
        })
      },
      gotoSearch() {
           uni.navigateTo({
             url: '/subpkg/search/search'
           })
         }
    }
  }
</script>

<style lang="scss">
  .cate-view{
    background-color: #FFFFFF;
  }
.scroll-view-container{
  display: flex;
}

.left-scroll-view{
  width: 120px;
  
  .left-scroll-view-item{
    background-color: #F7F7F7;
    line-height: 60px;
    text-align: center;
    font-size: 12px;
    
    &.active{
      background-color: #FFFFFF;
      position: relative;
      
      &::before{
        content: ' ';
        display: block;
        width: 3px;
        height: 30px;
        background-color: #C00000;
        position: absolute;
        top: 50%;
        left: 0;
        transform: translateY(-50%);
      }
    }
  }
}

.cate-lv2-title{
  font-size: 12px;
  font-weight: bold;
  text-align: center;
  padding: 15px 0;
}

.cate-lv3-list{
  display: flex;
  flex-wrap: wrap;
  .cate-lv3-item{
    width: 33.33%;
    display: flex;
    // 图片和文字纵向布局
    flex-direction: column;
    // 横向居中
    justify-content: center;
    align-items: center;
    margin-bottom: 10px;
    
    image{
      width: 60px;
      height: 60px;
    }
    text{
      font-size: 12px
    }
  }
}
</style>
